That package doesn’t exist in Debian jessie, which Whonix is based on.
See also:
Ok. Ths. I understand. What can you recomend me? I should choose any different wallet (which one?) or where i can read about how i can install official wallet?
It’s possible. I for one just do not have time to hand held you through this admittedly difficult process. That’s why I highlighted Whonix ™ - Anonymous Operating System.